Authors: Yuxin Cao Jinling Zhai Qichao Wang Hongmei Yuan Xi Huang
Publish Date: 2016/08/20
Volume: 245, Issue: 1, Pages: 31-44
Abstract
Laticifer is a special tissue in Hevea brasiliensis where natural rubber is biosynthesized and accumulated In young stems of epicormic shoots the differentiation of secondary laticifers can be induced by wounding which can be prevented when the wounding site is wrapped Using this system differentially expressed genes were screened by suppression subtractive hybridization SSH and macroarray analyses This led to the identification of several dehydrationrelated genes that could be involved in laticifer differentiation and/or latex biosynthesis including a NAC transcription factor termed as HbNAC1 Tissue sections confirmed that local tissue dehydration was a key signal for laticifer differentiation HbNAC1 was localized at the nucleus and showed strong transcriptional activity in yeast suggesting that HbNAC1 is a transcription factor Furthermore HbNAC1 was found to bind to the ciselement CACG in the promoter region of the gene encoding the small rubber particle protein SRPP Transgenic experiments also confirmed that HbNAC1 interacted with the SRPP promoter when coexpressed and enhanced expression of the reporter gene βglucuronidase occurred in planta In addition overexpression of HbNAC1 in tobacco plants conferred drought tolerance Together the data suggest that HbNAC1 might be involved in dehydrationinduced laticifer differentiation and latex biosynthesis
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